MAGNETIC CRYSTAL FOR RADIO WAVE ABSORBING MATERIAL AND RADIO WAVE ABSORBENT

摘要

Disclosed is a magnetic crystal for electromagnetic wave absorbing materials, having a structure of µ-M x Fe 2-x O 3 with 0 < x < 1, which has the same space group as that of an µ-Fe 2 O 3 crystal and which is derived from an µ-Fe 2 O 3 crystal by substituting a part of the Fe site therein with M. In this, M is a trivalent element having an effect of lowering the coercive force Hc of µ-Fe 2 O 3 crystal by the substitution. Concretely, the element M includes Al and Ga. An electromagnetic wave absorber having a packed structure of particles having such a substituent element M-added "M-substituted µ-Fe 2 O 3 crystal" as the magnetic phase may control the electromagnetic wave absorption peak frequency depending on the degree of substitution with the element M, and for example, the invention gives an electromagnetic wave absorber applicable to a 76 GHz band for on-vehicle radars.